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Ameba Arduino Calendar With Humidity and Temperature

Introduction: Ameba Arduino Calendar With Humidity and Temperature

We are going to make a clock with date along with humidity and temperature, and display the data in an I2C 16x2 LCD. We will get the time and date data from NTP server of NIST (National Institute of Standards and Technology - Boulder, Colorado United States). The humidity and temperature data will be read out from DHT22 sensor. We will get all these data once a minute.

Serial LCD - You can look for this LCD by searching "16x2 serial LCD" at eBay or Amazon.

DHT22 - This is a digital relative humidity and temperature sensor that has been used in many Arduino projects. Youc an find it in eBay or Amazon by searching for "DHT22". You can also use cheaper DHT11 for this project, DHT22 has however higher precision than DHT11.

Step 1: DHT22

DHT22 is a 4-pin sensor, the pinout connections are:

VCC - This pin will be connected to Ameba 3.3V output

Data - This is the data pin which will be connected to digital pin 2

N.C - Not connected pin

GND - Connect to ground of the board

Please note that a 4.7K - 10K resistor is usually required to use as a pullup from data pin to VCC. It can ensure a valid logic level when GPIO pin is switching from input to output. However we simplify and ignore this step as the DHT22 datasheet indicate we should not send any instruction to the sensor within one second to pass unstable status anyway. One 100nF capacitor can also be added between VCC and GND for wave filtering.

Step 2: Serial LCD

There are four wires in this serial LCD module and the connections to Aemba Arduino board is simple & straightforward:

GND - Board ground

VCC - Board 5V output

SDA - Board SDA pin (A4 )

SCL - Board SCL pin (A5)

Step 3: Final Wiring

The system connection figure and final wiring pictures are as shown above.